Is there an easy way to combine projects?

I used to have one big project, but at some point it was too big and would crush every 20 minutes. At the time it was set as a single xml file before I learned about composite.

Now I have 20 small projects and would like to bring them to a single project which I can run through Jenkins and develop load testing.

Is there an easy way to do that? I would need the services to be brought in as well (from the project tab), some are the same but some are different and may be in different levels of refactoring...